--- IO-AIO/AIO.pm 2006/10/24 16:35:04 1.73 +++ IO-AIO/AIO.pm 2006/10/26 12:38:04 1.78 @@ -136,7 +136,7 @@ aio_group aio_nop); our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush - min_parallel max_parallel max_outstanding nreqs); + min_parallel max_parallel nreqs); @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; @@ -428,9 +428,9 @@ =item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) Scans a directory (similar to C) but additionally tries to -separate the entries of directory C<$path> into two sets of names, ones -you can recurse into (directories or links to them), and ones you cannot -recurse into (everything else). +efficiently separate the entries of directory C<$path> into two sets of +names, directories you can recurse into (directories), and ones you cannot +recurse into (everything else, including symlinks to directories). C is a composite request that creates of many sub requests_ C<$maxreq> specifies the maximum number of outstanding aio requests that @@ -522,55 +522,35 @@ my (@dirs, @nondirs); - my ($statcb, $schedcb); - my $nreq = 0; - - my $statgrp = add $grp aio_group; - - $schedcb = sub { - if (@$entries) { - if ($nreq < $maxreq) { - my $ent = pop @$entries; - $nreq++; - add $statgrp aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) }; - } - } elsif (!$nreq) { - # finished - $statgrp->cancel; - undef $statcb; - undef $schedcb; - $grp->result (\@dirs, \@nondirs); - } + my $statgrp = add $grp aio_group sub { + $grp->result (\@dirs, \@nondirs); }; - $statcb = sub { - my ($status, $entry) = @_; - if ($status < 0) { - $nreq--; - push @nondirs, $entry; - &$schedcb; - } else { - # need to check for real directory - add $grp aio_lstat "$path/$entry", sub { - $nreq--; - - if (-d _) { - push @dirs, $entry; - - if (!--$ndirs) { - push @nondirs, @$entries; - $entries = []; + limit $statgrp $maxreq; + feed $statgrp sub { + return unless @$entries; + my $entry = pop @$entries; + + add $statgrp aio_stat "$path/$entry/.", sub { + if ($_[0] < 0) { + push @nondirs, $entry; + } else { + # need to check for real directory + add $statgrp aio_lstat "$path/$entry", sub { + if (-d _) { + push @dirs, $entry; + + unless (--$ndirs) { + push @nondirs, @$entries; + feed $statgrp; + } + } else { + push @nondirs, $entry; } - } else { - push @nondirs, $entry; } - - &$schedcb; } - } + }; }; - - &$schedcb while @$entries && $nreq < $maxreq; }; }; }; @@ -593,8 +573,6 @@ =item aio_group $callback->(...) -[EXPERIMENTAL] - This is a very special aio request: Instead of doing something, it is a container for other aio requests, which is useful if you want to bundle many requests into a single, composite, request with a definite callback @@ -706,10 +684,6 @@ =item * You must not add requests to a group from within the group callback (or any later time). -=item * This does not harmonise well with C, so best do -not combine C with it. Groups and feeders are recommended for -this kind of concurrency-limiting. - =back Their lifetime, simplified, looks like this: when they are empty, they @@ -734,6 +708,11 @@ Returns all its arguments. +=item $grp->cancel_subs + +Cancel all subrequests and clears any feeder, but not the group request +itself. Useful when you queued a lot of events but got a result early. + =item $grp->result (...) Set the result value(s) that will be passed to the group callback when all @@ -741,8 +720,6 @@ =item feed $grp $callback->($grp) -[VERY EXPERIMENTAL] - Sets a feeder/generator on this group: every group can have an attached generator that generates requests if idle. The idea behind this is that, although you could just queue as many requests as you want in a group, @@ -805,6 +782,9 @@ regularly. Returns the number of events processed. Returns immediately when no events are outstanding. +If not all requests were processed for whatever reason, the filehandle +will still be ready when C returns. + Example: Install an Event watcher that automatically calls IO::AIO::poll_cb with high priority: @@ -812,6 +792,22 @@ poll => 'r', async => 1, cb => \&IO::AIO::poll_cb); +=item IO::AIO::poll_some $max_requests + +Similar to C, but only processes up to C<$max_requests> requests +at a time. + +Useful if you want to ensure some level of interactiveness when perl is +not fast enough to process all requests in time. + +Example: Install an Event watcher that automatically calls +IO::AIO::poll_some with low priority, to ensure that other parts of the +program get the CPU sometimes even under high AIO load. + + Event->io (fd => IO::AIO::poll_fileno, + poll => 'r', nice => 1, + cb => sub { IO::AIO::poll_some 256 }); + =item IO::AIO::poll_wait Wait till the result filehandle becomes ready for reading (simply does a @@ -882,21 +878,22 @@ =item $oldnreqs = IO::AIO::max_outstanding $nreqs -[DEPRECATED] +[REMOVED] -Sets the maximum number of outstanding requests to C<$nreqs>. If you -try to queue up more than this number of requests, the caller will block until -some requests have been handled. +Pre-2.x versions used max_outstanding for a crude request queue length limit. -The default is very large, so normally there is no practical limit. If you -queue up many requests in a loop it often improves speed if you set -this to a relatively low number, such as C<100>. - -This function does not work well together with C's, and their -feeder interface is better suited to limiting concurrency, so do not use -this function. +In 2.x+ you are advised to use a group and a feeder to limit +concurrency. The max_outstanding feature ran very unstable (endless +recursions causing segfaults, bad interaction with groups etc.) and was +removed. -Under normal circumstances you don't need to call this function. +I am deeply sorry, but I am still on the hunt for a good limiting interface. + +Original description was as follows: + +Sets the maximum number of outstanding requests to C<$nreqs>. If you try +to queue up more than this number of requests, the caller will block until +some requests have been handled. =back